The invention provides a ridable bouncing apparatus which has great energy-storage capacity, and whose thrust function is radically scalable to suit the weights and inclinations of a variety of riders. These benefits are achieved through the use of a compound tension spring, and a set of innovations extending to all components of the system which permit the potential benefits of such a spring to be safely and conveniently realized.
The ridable bouncing apparatus includes a carriage assembly that can support a person; a foot alternately retracting toward and extending away from the carriage assembly; and a thrust assembly. The thrust assembly is mounted to the carriage assembly and to the foot and has a force that impels the extension and resists the retraction. The bouncing apparatus includes a shield member protecting the person from contact with at least a portion of the thrust assembly. The thrust assembly in some embodiments has at least one tension element that supplies a tension force. In such embodiments, the bouncing apparatus has an access feature that enables engagement and disengagement of the tension element. In preferred embodiments, the retraction and extension are co-linear.
The tension assembly preferably includes a linkage and a spring, with the linkage connecting the foot to the carriage assembly and limiting the motion of the foot to a single linear trajectory, motion along which is either retraction or extension, and with the spring acting on the linkage to impel the extension and resist the retraction. The spring preferably includes a set of elongated elastomeric elements, and is scaled by adding or removing individual elements to or from the operative set. The access features are provided to make this operation convenient. In some embodiments these features are apertures which permit spring elements to be physically added to or removed from the apparatus; in some cases doors are provided to cover such apertures during operation. Other embodiments include mechanisms which permit switching of individual spring elements between engaged and disengaged states but leave disengaged elements mounted on the apparatus.
The foot is preferably a relatively large foot mounted on a universal joint, provided both to permit adequate traction when the apparatus is tilted and to reduce ground loading. This reduces the potential for damage to floors and permits use on relatively soft ground such as lawns.
A shield requirement exists because the mounts for the spring can be bulky and at least one of them must move quickly, relative to the carriage. The requirement can be met in at least two different ways. As discussed below, one form uses a conventional piston linkage, but replaces the conventional slender tube frame with a much larger hollow column whose interior serves as an enclosed channel for the upper mount. Also as discussed below, another form uses a novel scissor-lift linkage which permits the entire thrust assembly to be mounted beneath the pedal platform, and thus exploits the pedal platform itself as a shield.
In some embodiments such as, for example, some pogo apparatuses, the carriage assembly can include a vertically extending support structure and have pedals on which a rider stands and a handle that the rider grasps for use as a control feature. A bounceboard variant of a scissor-lift embodiment has no handle but includes control features usable by pedal contact.
The thrust assembly can include a piston, alternately retracting upwardly toward and extending downwardly away from the carriage assembly, with the foot at a distal end. The thrust assembly can further include at least one bearing, mounted between the carriage assembly and the piston, for easing the retraction and extension and for limiting lateral movement of the piston relative to the carriage assembly. The thrust assembly can further include a set of tension elements mounted to the carriage assembly and to the piston, thereby impelling the extension and resisting the retraction. Preferably, each tension element is mounted so as to permit it to be easily attached to or detached from at least one attachment point, to add it to or remove it from (as applicable) a set of operative tension elements.
For piston embodiments, there are two distinct functions which each require a member rising vertically above the pedal platform. This creates an opportunity to improve efficiency through the introduction of a synergistic multifunction component. The two functions are support of a handle and shielding of the rider from the thrust assembly. A handle is a primary control feature in pogo embodiments, is used in all control modes (roll, pitch, and yaw), and is subjected to substantial forces - particularly a backwards pitching force applied by jumpers who tilt the pogo forward during jumping. In extreme cases this tilt can be as much as thirty degrees forward from the angle of travel. This generates a torque of up to about 600 foot-pounds. To counteract this torque, a control force of approximately 100 pounds must be applied to the handle. This exceeds the forces encountered in extant pogo sticks by a factor of about four (because this is the ratio of the corresponding thrust limits). Consequently, the beam-strength requirement in this longitudinal direction is also quadrupled.
A solution for meeting these two requirements would be to provide strengthened but still relatively slender tubular frame members and a capacious but relatively weak plastic cowl around the trajectory of the upper mount. Such an approach would oblige the designer to use much more material, or a much stronger material, for the handle stem - imposing a penalty of weight or cost. It would also result in a relatively fragile shield member likely to fracture under the sort of abuse which can be anticipated for a pogo stick on the playground. A more effective and efficient solution, disclosed herein, is the use of a monocoque structural member. Such members are used in applications which involve both structural and containment requirements, and achieve the structural function without the use of distinct structural members, by distributing their material over a suitably-designed containing surface.
The frame discussed in the preferred embodiment is such a monocoque member, configured to provide the required beam strength in the longitudinal direction and whose internal cavity also provides the required enclosure, or channel, for a suitably-configured thrust assembly. It is preferably an aluminum extrusion, though an extruded or molded column of high-impact plastic would also be viable. The relatively enormous structural depth of such a member ensures that ample beam strength is provided by any gauge of material suitable as a barrier; hence the beam function is effectively obtained for free. Another efficiency of the form is reduced bulk (since the dead space in and around tubular frame members is avoided). Another significant benefit is that the deep and narrow configuration of the column which maximizes longitudinal beam strength also provides an ergonomically optimal configuration of the thrust assembly. That is, the large sectional area of the thrust assembly fits most comfortably between a rider""s feet and knees and interferes least with the biomechanics of jumping when it is so configured.
Further in those and other embodiments, the access feature can include the channel, when the channel is adapted to enable disengagement and engagement of the tension element by, for example, allowing immediate access to the tension element for adjustment of the tension force. In this regard, the frame can have a panel that can be displaced to allow the immediate access. The access feature can also further include upper and lower mounts within the channel, to which each tension element can be mounted, each of the mounts having an opening through which ends of the tension elements can be passed. The rider can therefore displace the panel and reduce the tension force by removing (disengaging) at least one tension element. Similarly, the rider can displace the panel and increase the tension force by adding (engaging) another tension element, or replacing a previously removed (previously disengaged) tension element. In this regard, each tension element can be individually mountable and demountable.
In other embodiments, the access feature can include an assembly that mechanically engages and disengages tension elements. In such embodiments, it is preferable that the tension elements are not bundled and that the mounts are not bulky. While any suitable mechanism can be used, a preferred embodiment includes snags which have suitable control features at a location accessible by the rider. The snags can be operated by means of the control features to catch hold of a fixture attached to the end of each tension element. Also preferably, a storage rack can be used to put the fixtures of the disengaged tension elements precisely where the snags need them to be when the piston is arrested. The rack can be attached to the piston. Accordingly, disengaged elements remain stretched between the rack and the upper mount, with some tension keeping them snug, and travel up and down with the piston. Preferably, the ends of the tension elements are provided with snaggable fixtures that seat up against the storage rack when the elements are disengaged.
Piston embodiments can employ an arrest system to halt the extension of the piston at some pre-determined limit. In this regard, the thrust assembly can further include an arresting assembly for that purpose. Two exemplary systems are described herein: an impact system and a strap system. In the impact system, the arresting assembly can include a feature, on the carriage assembly, having an upper face, and a feature, on the piston at a distance from the distal end, having a lower face. Contact of the faces limits the extension of the piston downwardly away from the carriage assembly. Alternatively, in the strap system, the arresting assembly can include an elongated tensile element such as, for example, a cord or strap, having an upper end attached to the carriage assembly and a lower end attached to the piston. Extension of the piston downwardly away from the carriage assembly is limited when the strap becomes taut. In both cases provision can be made for the absorption of shock.
The invention provides for adjustable arresting assemblies as well. The arrest feature in some embodiments is selectably attachable to the piston shaft at any one of a set of possible positions, to provide for adjustment of the piston travel. For example, the tension element can be attached at one end to the carriage assembly by a carriage mount and at another end to the piston by a piston mount, and a length of piston travel can be adjusted. In this regard, some embodiments can include a piston having a central shaft with the piston mount attached to the shaft, and the piston mount can slide vertically relative to the shaft, through a range of positions, and be secured to the shaft at one of the positions. In some embodiments, the tension element is pre-tensioned, and the arresting assembly effects the pre-tension. In some of these embodiments, the pre-tension force can be adjusted independently of the adjustment for piston travel.
In some scissor-lift apparatuses, the carriage assembly can include a longitudinal platform that supports the rider in a standing position with his or her feet longitudinally separated with at least one foot transversely oriented, and have a control feature for maintaining contact between the platform and the rider""s feet and for directing the platform during operation of the apparatus. In other scissor-lift apparatuses, the carriage assembly can include a vertically extending support structure, similar to the structure discussed above with regard to the pogo apparatuses, that has pedals on which a rider stands and a handle that the rider grasps for use as a control feature.
Further in these and other embodiments, the thrust assembly includes a scissor-lift assembly, mounted to the carriage assembly and to the foot, for enabling the retraction and the extension. The scissor-lift assembly can include at least one tension element impelling the extension and resisting the retraction.
The scissor-lift assembly includes a vertically ordered set of arm pairs, with each arm pair having paired arms joined to one another by a medial hinge having a horizontal axis. An uppermost arm pair of the set is attached to the carriage assembly by a fixed hinge at a proximal end of one arm of the pair and by a sliding hinge at a proximal end of another arm of the pair. A lowest arm pair has a short arm having an operable length terminating at the medial hinge and a long arm attached at a distal end to the foot. The arms are connected so that the foot is beneath the fixed hinge; this ensures that the foot is constrained to a linear trajectory. While in some embodiments the uppermost arm pair is also the lowest arm pair, thus providing a single arm pair, in other embodiments the set includes a plurality of arm pairs, with each arm pair having at least one proximal arm end and at least one distal arm end. Each arm pair can be joined to an adjacent arm pair of the plurality in that the proximal arm end of a lower pair of the joined pairs is attached by at least one hinge to the distal arm end of an upper pair of the joined pairs.
In scissor-lift embodiments, the shield member is provided by a platform of the carriage assembly, in that the scissor-lift assembly is mounted to a bottom surface of the platform, shielding the rider from the scissor-lift assembly.
Further in scissor-lift embodiments which employ a tension spring, the access feature can include the tension element mounts having an opening through which an end of the tension element can be passed. The rider can therefore reduce the tension force by removing (disengaging) at least one tension element from the mounts. Similarly, the rider can increase the tension force by adding (engaging) another tension element on the mounts, or replacing a previously removed (previously disengaged) tension element. In this regard, each tension element can be individually mountable and demountable.